Do you just add the person in question to your friends and see how they respond? Or is there a way to communicate about this before?

If this has been adressed before, sorry, I couldn't find it.

You just add em to your list, there's no approval or anything that needs to happen like on myspace. They'll get a PQ telling them that you've added them as a friend, then they can add you back if they want to.

There's no real benefit to it yet (it's an incomplete feature) other than being able to collect a long list of 'friends'